The present invention relates to an apparatus for wrapping compressible articles, such as stacked printed products, with a web-like wrapping material.
An apparatus of the above type is known from EP-A-0 120 251 and the corresponding U.S. Pat. No. 4,738,078. In the known apparatus, the articles which are to be wrapped are introduced in the compressed state into a wrap-around channel, which is formed by a bearing table and a pressure-exerting arrangement assigned thereto, and at the same time are wrapped in the form of a U by a foil or web-like material. A guide arrangement then guides the material web, with the formation of a material-web loop, along the trailing side of the article, as seen in the conveying direction, and at the same time forms, on the one hand, a first material-web section and, on the other hand, a second material-web section, which runs on the trailing side of the article and of which the length is greater than the dimension of the article in the longitudinal direction of said second material-web section. The tensioned material-web sections are secured by means of retaining devices, which for this purpose have pins which pierce the material web. The material web is then severed between the two retaining devices by means of a stationary cutting arrangement. Once the stationary pressure-exerting arrangement has been raised, the bearing means, with the wrapped article and the second material-web section retained under tensile stressing, is rotated through 180.degree.. As the wrapped article is conveyed from the bearing table onto a belt conveyor, the projecting end section of the second material-web section is wrapped around against the base of the article once it has been released.
As the bearing means is rotated, the article is retained solely by its own weight and the tensioned, and secured, second material-web section. This requires, on the one hand, a material web of certain strength and, on the other hand, in order to allow quick rotation, the at least virtually central arrangement of the article on the bearing table, with the result that the axis of rotation of said table runs at least approximately through the center of gravity of the article.
Taking this prior art as departure point, it is an object of the present invention to develop the apparatus of the described type such that, even when a less strong, and thus less expensive, material web is used, quicker rotation of the bearing means, and thus a reduction in the time necessary for wrapping the article, is made possible.